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1.
Al(Ⅲ)-CAS-OP-PVA体系分光光度法测定沸石分子筛中的铝   总被引:7,自引:0,他引:7  
研究了在聚乙二醇辛基苯基醚(乳化剂OP)及聚乙烯醇(PVA)存在下铝(Ⅲ)与铬天青S(CAS)的显色反应。在pH5.3的HAc-NaAc缓冲介质中,题示体系最大吸收波长λmax=612nm,对比度Δλ=102nm,表观摩尔吸光系数ε612nm=2.84×104L·mol-1·cm-1。铝(Ⅲ)浓度在0-0.60μg/mL范围内遵守比耳定律。本法已成功地用于沸石分子筛中铝含量的测定,结果良好。该法具有稳定性高、准确度好的特点。  相似文献   

2.
研究了7-碘-8-羟基喹啉-5-磺酸(H2QSI)在乙醇存在下分光光度法测定钒(V)的最佳条件。在乙醇存在下pH4的硫酸介质中,(H2QSI)与V(V)形成了红棕色配合物,最大吸收位于506nm处,表观摩尔吸光系数εmax=2.9×10^3L·mol^-1·cm^-1,有色配合物组成为V(V):(H2QSI)=1:3。钒(V)在0-14μg/25mL符合比耳定律。本法用于钢样中的测定,结果满意。H2QSI是光度分析中的一种显色剂,近年来,8-羟基喹啉类试剂用于钒(V)的测定尚未见报道。本文研究了V(V)与H2QSI的显色反应条件及组成,在pH4的乙醇介质中,V(V)与H2QSI生成红棕色配合物,ε506nm=2.910^3L·mol^-1·cm^-1。本方法用于低碳合金钢中钒的测定,结果满意。  相似文献   

3.
5-Br-PADAP分光光度法测定废水中微量铬(Ⅵ)的研究   总被引:3,自引:0,他引:3  
本文研究了2-[2-(5-溴吡啶)倡氮]-5-二乙氨基酸(5-Br-PADAP)与Cr(Ⅳ)的显色反应,在阳离子表面活性刑十六烷基三甲基溴化铵(CTB)存在下,于pH4.0的HAc-NaAc缓冲介质中,Cr(Ⅳ)与该试剂生成1:2的紫色配合物,其配合物的最大吸收波长位于592nm,摩尔吸光系数为4.86×104L·mol-1·cm-1,铬(Ⅳ)含量在0—10μg/25mL范围内符合比耳定律。方法用于水样中微量铬的测定。  相似文献   

4.
研究了新试剂5-(偶氮苯)-8-(4-硝基-1-重氮苯)-氨基喹啉(PANPAQ)与铜的显色反应,在弱碱性介质中,吐温-80存在下,PANPAQ与Cu(Ⅱ)反应生成2:1紫色络合物,λmax=615nm,ε=5.19×10^4L·mol^-1·cm^-1,铜含量在0-15μg/25mL内符合比耳定律,方法用于生物样品中铜的测定,结果满意。  相似文献   

5.
铝-氟-DSPCF分光光度法测定地下水中铝   总被引:1,自引:1,他引:0  
本文研究了铝-氟-1,5-二(2-羟基-5-磺基苯基)-3-氰基甲(DSPCF)的显色反应。在硼酸-硼砂介质中,显色反应灵敏,最大吸收波长为610nm,配合物的表现摩尔吸光系数5.0×104,铝含量在0-15μg/25mL符合比尔定律。该法用于地下水中微量铝的测定获得了满意结果。  相似文献   

6.
硅钼蓝光度法测定沸石分子筛中的硅   总被引:6,自引:0,他引:6  
提出沸石分子筛中硅含量测定的硅钼蓝光度法。方法基于盐酸介质中Si(Ⅳ)与钼酸铵形成硅钼黄杂多酸后,用抗坏血酸还原硅钼黄形成硅钼蓝的原理进行硅的测定。本文实验条件下,体系的λmax位于770nm,表观摩尔吸光系数εmax=1.92×10^4L·mol^-1·cm^-1,硅量在0-0.60μg/mL范围内遵守比耳定律。本文提出的新方法已成功地用于某些沸石分子筛中的硅测定。  相似文献   

7.
合成了新试剂1-(2-羟基苯基)-3-[4-(苯基偶氮)苯基]-三氮烯(HPAPT),在氢氧化钠碱性介质中,该试剂与溴化十六烷基三甲铵(CTMAB)形成1∶3的紫红色离子缔合物。λmax位于565nm,表观摩尔吸光系数为1.59×104L·mol-1·cm-1,CTMAB含量在3—29.16mg·L-1范围内符合比耳定律。测定了显色体系CTMAB的临界胶束浓度是1.50×10-4mol·L-1。  相似文献   

8.
铜与洋茉莉基荧光酮反应的分光光度研究及应用   总被引:4,自引:1,他引:3  
本文研究了在CPB存在下洋茉莉基荧光酮(PIF)与铜的显色反应。结果表明:在pH5.8-6.6的六次甲基四胺-HCl缓冲介质中,Cu^2 与PIF形成1:2的蓝紫色配合物,以524nm为参比波长、582nm为测定波长,用双波长吸光光度法测得表观摩尔吸光系数为1.11×10^5L·mol^-1·cm^-1。铜在0-0.20μg/mL范围内服从比耳定律。用于高纯稀土氧化物中微量铜的测定,相对误差不大于3.7%,相对标准偏差不大于2.0%(n=6)。  相似文献   

9.
本文研究了溴化5-[4-(4-吡啶丁氧基)苯基]-10,15,20-三苯基卟啉与Cu2+的显色反应条件,络合物最大吸收波长为414nm,试剂(H4P2+)最大吸收波长为446nm。对比度为32nm,试剂与铜络合比为1∶1,表观摩尔吸光系数为2.5×105L·mol-1·cm-1,铜含量在0.2—1.0μg/10mL内符合比耳定律,可用于痕量铜的测定。  相似文献   

10.
双水相体系中Cu(Ⅱ)的显色反应研究   总被引:2,自引:0,他引:2  
田瑞启 《光谱实验室》1999,16(3):302-305
本文研究了铬黑T(EBT)作萃取剂和显色剂,在聚乙二醇-2000(PEG)-Na2SO4-EBT双水相体系中Cu(Ⅱ)的显色反应条件及应用,实验结果表明,在pH8.5缓冲溶液中,将Cu(Ⅱ)络合物从水溶液中萃取到PEG相,其最大吸收波长位于560nm,摩尔吸光系数为3.05×10^4L·mol^-1·cm^-1,此法用于铝合金中铜的测定,获得了满意结果。  相似文献   

11.
Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.  相似文献   

12.
The differences of the pitch and duration of Chinese syllables between Putonghua (PTH) and Taiwan Mandarin (TM) were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that: For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.  相似文献   

13.
Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.  相似文献   

14.
It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].  相似文献   

15.
A multi-conjugate adaptive optics (MCAO) can offer a possibility of widening field of view (FOV) characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle's expressions of two deformable mirrors (DMs) MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.  相似文献   

16.
Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.  相似文献   

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19.
Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122: 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM (Scanning Electron Acoustic Microscopy) signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α (α is the radius of the focused electron beam). Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.  相似文献   

20.
Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.  相似文献   

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